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katherine-medina

IJMS | Free Full-Text | The Combination of Catechin and Epicatechin Gallate f... - 1 views

  • efflux
  • efflux pumps
    • katherine-medina
       
      Wow, so MRSA can literally pump out antibiotics.
  • The advantage of the agents is that there is little or no direct selective pressure, and thus resistant strains are less likely to emerge
  • ...17 more annotations...
  • Figure 1
    • katherine-medina
       
      I could do something similar to this in a Petree dish like the photo above.
  • Baicalin [8], diterpenes [9], tellimagrandin I [10], corilagin [11], tripeptide [12], epigallocatechin gallate (EGCg) [13] and epicatechin gallat
  • The extracts and compounds from hawthorn have been reported to show a variety of pharmacological activities, such as a protective effect on patients with heart failure [17], as well as an increased force of myocardial contraction [18], improved coronary circulation [19], antioxidant effects [20] and antimicrobial activities [21].
  • For example, galloy catechins, such as ECg and Cg, reduced the high MIC level of β-lactams to the antibiotic breakpoint or even lower than the breakpoint [14,15,26,27], but non-galloylated catechins, such as C and EC, had no such effect
    • katherine-medina
       
      use galloy catechins
  • WHO-2 but ECg (32 mg/L) increased the drug accumulation
    • katherine-medina
       
      So, at this specific concentration ECg helped with increasing the amount of antibiotic, but not necessarily assisting the ability of the antibiotic to do damage.
  • C or ECg (32 mg/L) in combination with oxacillin produced FICIs of more than 0.5 or 0.5, demonstrating no or very weak ILSMR effect.
  • via inhibiting mRNA expression of efflux pump genes,
  • Some natural products can enhance the efficacy of β-lactam antibiotics, and therefore they are termed intensifiers of β-lactam susceptibility in MRSA
    • katherine-medina
       
      I would like to look into using antibiotics that are currently available to the public, and trying to enhance their ability to fight bacteria through the use of certain polyphenols or some other type of natural product.
  • In traditional Chinese medicine, hawthorn is used as a peptic agent for stimulating digestion and promoting the function of the stomach, improving blood circulation and removing blood stasis
  • We also found that when C combined with ECg, the ILSMR effect was markedly increased and the ILSMR effect of the combination (C and ECg) was enhanced with the increase in the concentration of C, with a higher concentration of C resulting in a lower FICI.
  • Overall, the different abilities of C and EGC to potentiate the ILSMR effect of ECg was presumed to be due to the difference in steric hindrance provided by the hydroxy groups in the B ring of these compounds.
  • Our results showed that C in combination with ECg could significantly reduce the MIC of these six antibiotics against almost all of the clinical MRSA strains
  • These results are significant since they demonstrate the possibility that these antibiotics can be used in the clinic when combined with C and ECg.
    • katherine-medina
       
      I wonder if they have started implementing this in hospitals.
  • . Therefore, a criterion suitable for more than two compounds should be investigated in the future.
    • katherine-medina
       
      I think that this will be a useful article to go back to when looking towards developing further ideas for experiments.
  • he above results suggested the ILSMR effect of C and ECg was probably related to the inhibition of three pumps’ mRNA expressions. Which pump(s) played a more important role should be further investigated in the future experiments.
    • katherine-medina
       
      Interesting
  • Herein, our results showed that reserpine down-regulated mRNA expressions of norA and norC, but not abcA, and C, in combination with ECg, down-regulated mRNA expressions of norA, norC and abcA among eight efflux pumps, while ECg or C alone could not.
  • Sh
  •  
    An article discussing the affects of combining polyphenols with antibiotics in order to fight against MRSA.
katherine-medina

Peptidomimetic antibiotics disrupt the lipopolysaccharide transport bridge of drug-resi... - 0 views

  • Recently, naturally occurring peptides were proposed to interfere with the function of proteins constituting the lipopolysaccharide
  • periplasmic
    • katherine-medina
       
      The space in between the inner and outer membranes of gram-negative bacteria
  • Thanatin, a 21–amino acid defense peptide isolated from the gut of the hemipteran insect Podisus maculiventris (18), exhibits broad-spectrum antimicrobial activity
    • katherine-medina
       
      I wonder what other peptides do so as well?
  • ...7 more annotations...
  • We hypothesized that thanatin mainly acts as a competitive inhibitor of the protein-protein interactions mediating the Lpt bridge assembly
  • Thanatin, however, is not a suitable drug candidate for further development due to poor drug-like properties and rapid emergence of resistance
    • katherine-medina
       
      Why/How does thanatin have poor drug-like properties?
  • β-jellyroll
    • katherine-medina
       
      structure found in proteins
  • Here, we introduce thanatin-derived synthetic macrocyclic peptides found after a substantial medicinal chemistry effort.
    • katherine-medina
       
      Essentially they synthetically created it
  • Development of resistance against thanatin was observed after 1 day of passaging in both E. coli and K. pneumoniae and is characterized by a spontaneous FOR of 1.2 × 10−6 for E. coli at 4× MIC
    • katherine-medina
       
      That is kinda scary to think about
  • genome sequencing of a diverse panel of thanatin-resistant strains confirmed on-target modifications on LptA as the main resistance determinant in E. coli and K. pneumoniae.
  • The attractive in vitro and in vivo profile of these new antibiotics, coupled with their novel mechanism of action, showing no cross-resistance to standard of care antibiotics, may provide clinicians with additional treatment options to fight AMR, either in combination with SoC or as stand-alone antibiotics.
    • katherine-medina
       
      It is interesting to look around that these other methods that can fight off bacteria.
  •  
    An article showing a new class of antibiotics known as a peptidomimetic antibiotic.
katherine-medina

Restoring the activity of the antibiotic aztreonam using the polyphenol epigallocatechi... - 0 views

  • epigallocatechin gallate (EGCG) against multidrug-resistant clinical isolates of Pseudomonas aeruginosa
    • katherine-medina
       
      Epigallocatechin (EGCG) is a type of catechin or a natural phenol antioxidant. It is commonly found in tea leaves, plums, apple skin, and onions. Sidenote this bacteria is found in green tea
  • However, with resistance increasing against many classes of antibiotic, clinicians often use multiple combinations to treat critically ill patients
  • relatively low toxicity of EGCG to human keratinocytes and G. mellonella larvae.
  • ...12 more annotations...
  • . EGCG was able to restore the activity of aztreonam against MDR P. aeruginosa . The data presented support further evaluation of the aztreonam–EGCG combination and highlight its potential for use in clinical medici
  • Polyphenols
    • katherine-medina
       
      These are bioactive compounds that are found in fruits and leaves of plants. The main focus of this paper is a type of polyphenol.
  • with EGCG in checkerboard assays, susceptibility increased in P. aeruginosa (n=16, 100%), with the combination proving synergistic in all strains tested
    • katherine-medina
       
      Wow. for how much it increased the susceptibility.
  • Another option to restore the activity of aztreonam against bacterial strains with multiple resistance mechanisms would be to use polyphenols
  • he results demonstrate that synergy between aztreonam and EGCG exists [fractional inhibitory concentration indices (FICIs) 0.02-0.5], with the combination affording significantly (P=<0.05) enhanced bacterial killing, with a >3 log10 reduction in colony-forming units ml−1 at 24 h
  • To access synergy between aztreonam and EGCG, checkerboard assays were performed
  • Chemicals, media, bacterial isolates and animals
    • katherine-medina
       
      Really important to look back at these methods because even though it may not be feasible for me to do an experiment like this one, it still has valuable information for me to look at.
  • Synergy was also found between EGCG and the third-generation cephalosporin, cefotaxime
  • with scores of 64 and 56 out of a maximum of 64 for strains PA2 and PA6, respectively.
  • the increased activity may also be due to the inhibition of the non-mevalonate pathway, resulting in increased susceptibility to aztreonam.
  • Overall, the G. mellonella assays demonstrated that the aztreonam–EGCG combination was superior to monotherapy with either agent against every isolate tested, with significantly lower larval mortality rates
  • In conclusion, the results from this study demonstrate that synergy exists between aztreonam and EGCG against MDR clinical strains of P. aeruginosa in vitro and in vivo. EGCG is also able to restore the antibacterial activity of aztreonam to concentrations below the EUCAST susceptibility breakpoint for P. aeruginosa , potentially expanding and extending its useful therapeutic lifespan. Further work should be undertaken to determine if this combination has the potential to treat clinical infections caused by MDR P. aeruginosa .
    • katherine-medina
       
      My final thought for this article is as follows: 1. This brings up a very interesting topic for me to dig into (polyphenols & antibiotics)
  •  
    A gateway article for me to further my search into the scientific realm involving polyphenols that aid antibiotics.
katherine-medina

(1) Polyphenolic Secondary Metabolites Synergize the Activity of Commercial A... - 1 views

  •  
    An article showing how different polyphenols can enhance antibiotics.
katherine-medina

Full article: Effect of Dandelion root extract on growth performance, immune function a... - 0 views

  • From days 12 to 14 and days 26 to 28, approximately 100 g of faeces was collected from each pen for 3 days and the faecal samples were stored at −20°C. The 3-d faecal collection was pooled by pen and then dried at 65°C for 72 h.
  • From days 12 to 14 and days 26 to 28, approximately 100 g of faeces was collected from each pen for 3 days and the faecal samples were stored at −20°C. The 3-d faecal collection was pooled by pen and then dried at 65°C for 72 h.
    • katherine-medina
       
      Kinda gross, but interesting to know how and when the collected the "feces."
  • There were no differences in the ATTD of GE, CP, NDF and ADF among the three treatments.
    • katherine-medina
       
      Interesting that there was no difference between the three groups in that category.
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  • uring days 15–28, pigs in the CHE group had lower (P < .05) diarrhoea frequency compared with those in the NC treatment, and dietary CHE supplementation decreased the diarrhoea frequency by 63.62% and 57.82% compared with the NC and PC groups, respectively
    • katherine-medina
       
      So the Chinese herbal extract did a better job at reducing the diarrhoea frequency by 63.62 and 57.82% in comparison to the NC and PC groups.
  • Moreover, the concentration of IL-6 in serum in pigs fed the CHE diet was greater (P < .05) than those fed the NC diet.
  • There were no differences in the concentrations of IgA, IgG, IgM, GSH-PX, MDA, TNF-α, IL-4 and IL-1β among the three treatments.
  • Furthermore, pigs in the CHE group had greater (P < .05) formic acid, propionate and butyrate concentrations in faeces compared with pigs in the PC group, and had greater (P < .05) formic acid, butyrate and valerate concentrations in faeces compared with pigs in the NC group
    • katherine-medina
       
      Cool to note that the CHE group had a lower lactic acid concentration in comparison to the PC group.
  • Pigs in the CHE group showed increased relative abundance of Sytrophococcus on genus level, and decreased (P < .05) relative abundance of Clostridiaceae_1
  • In addition, relative abundances of genus Selenomonas, Alloprevotella, Prevotella_2, Rjkenellaceae, and Kitasatospora all increased in faecal samples when pigs fed the PC diet.
  • CHE supplementation decreased the diarrhoea frequency of pigs compared with diets with or without antibiotics supplemented. Some previous studies also reported the positive effects of dietary Chinese herbs supplementation on diarrhoea frequency of weaned pigs
  • he increased concentrations of immune markers in serum and faecal SCFAs in weaned pigs consumed CHE in our study may explain the positive effects of CHE supplementation on diarrhoea frequency and nutrient digestibility
  • but decreased the incidence of diarrhoea and increased digestibility of some nutrients.
  • In addition, CHE supplementation improved faecal SCFAs concentrations and immune function of weaned pigs, and shaped faecal microbial community in weaned pigs. As a result, the traditional Chinese herb medicine, CHE, could act as a potential alternative to the antibiotics such as aureomycin used in weaned pig diets.
    • katherine-medina
       
      I do quite enjoy this closing statement, so in summary CHE works to decrease diarrhoea in weened pigs.
  •  
    An article showing that pigs who ate CHE had a significant decrease in diahrroea.
  •  
    Super interesting. Just remember that experimentation on mammals where diet is altered, etc... is a super tightrope walk. It is almost impossible to get those approved. You would have to really dig into the ISEF rules on that. However, you can always think about ways to transfer ideas and concepts down to a "lower" animal model for many studies.
katherine-medina

Frontiers | Dietary Polyphenols and Their Role in Oxidative Stress-Induced Human Diseas... - 1 views

  • phenolic acids, flavonoids, catechins, tannins, lignans, stilbenes and anthocyanidins
  • They possess antioxidant, chemopreventive and a wide range of pharmacological properties (
  • Over 8,000 polyphenols have been reported from plants, out of several hundreds of polyphenols exist in human diets
  • ...25 more annotations...
  • Organic compounds bearing an aromatic ring with at least one hydroxyl group are termed as “phenolics”. In case, a compound possesses one or more aromatic rings having more than one hydroxyl group are called polyphenols (or polyphenolic compounds).
  • As per the C1-C6 or C3-C6 backbone, they are usually referred to as derivatives of benzoic acid or cinnamic acid
  • However, the role of the dietary polyphenols of their antioxidant abilities is still unclear.
    • katherine-medina
       
      How exactly is the role of antioxidants unclear?
  • Increased intake of foods containing polyphenols (for example, quercetin, epigallocatechin-3-gallate, resveratrol, cyanidin etc.) has been claimed to lower the incidence of a majority of chronic oxidative cellular damage, DNA damage, tissue inflammations, various cancers, viral/bacterial infections, and neurodegenerative diseases
    • katherine-medina
       
      So an increase of foods with natural extracts, so just plain vegetables that are not processed.
  • γ rays
    • katherine-medina
       
      I had no idea these were a thing.
  • This review specifically focuses a current understanding on the dietary sources of polyphenols and their protective effects including mechanisms of action against various major human diseases.
  • ROS when increased or excessively produced can cause oxidative changes/damages to all cellular macromolecules
  • Several antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) aid in the removal of free radicals
  • Peroxynitrite can also destroy lipoproteins and causes lipid peroxidation of cell membranes
  • ROS can also affect protein synthesis and protein functions. Protein oxidation can result in amino acid modifications
  • Flavonoids are further classified into different subgroups based on their structures such as flavan-3-ols (examples: catechin, epicatechin, epigallocatechin), isoflavones (examples: genistein, genistin, daidzenin, daidzin, biochanin A, formononetin), flavones (examples: luteolin, apigenin, chrysin), flavonones (examples: hesperetin, naringenin), flavonols (examples: quercetin, kaempferol, galangin, fisetin, myricetin), flavononol (example: taxifolin), flavylium salts (examples: cyanidin, cyanin, pelargonidin), and flavanones (examples: hesperetin, naringenin, eriodictyol, isosakuranetin)
    • katherine-medina
       
      WOW so flavonoids have a large variety and classes.
  • urther, OS exerts deleterious effects on DNA leading to the formation of DNA lesions, which can result in genomic instability and consequently lead to cell death.
  • Polyphenols are found naturally in fruits and vegetables such as cereals, pulses, dried legumes, spinach, tomatoes, beans, nuts, peppermint, cinnamon, pears, cherries, oranges, apples, red wine, tea, cocoa, coffee and so on (Arts and Hollman, 2005; Scalbert et al., 2005). Polyphenols are classified into different groups depending on the number of aromatic (phenolic) rings they contain and the structural elements that connect these rings. They are broadly grouped into phenolic acids, flavonoids, stilbenes and lignans
    • katherine-medina
       
      SO each polyphenol has a different number of phenolic rings. What is the difference between the different polyphenols such as phenolic acid, flavonoids, stilbenes and lignans. I think that I should look at which of these groups are more effective when working with antibiotics as a way to aid them in the fight against resistant bacterias.
  • In plant derived polyphenolic compounds, flavonoids comprise the largest group with an approximately 10,000 natural analogues
  • Dietary supplements containing elevated amounts of flavonoids from strawberries, lettuce, or blueberries aid in the reversal of age-related discrepancies in the brain and behavioral control in aged rats
  • Tea catechins
    • katherine-medina
       
      I ha e looked into these a bit, but I did not know that they can help with neurodegenerative diseases.
  • reduced glutathione (GSH), and on membrane sulphydryl (-SH) group in humans has been reported by Maurya and Rizvi (2009).
  • OS can be the primary or secondary reason for various CVDs. Preclinical evidence support that OS is linked to a variety of CVDs, including atherosclerosis, ischemia, stroke, cardiomyopathy, cardiac hypertrophy, and hypertension, as well as congestive heart failure
  • Dietary flavonoids may reduce endothelial disorders linked with various risk factors for atherosclerosis before plaque creation
  • The polyphenols of Hibiscus sabdariffa weaken diabetic nephropathy in terms of serum lipid profile and kidney oxidative markers
  • . Studies suggest that a diet that includes regular consumption of fruits and vegetables (rich in polyphenols such as catechins, resveratrol, ellagic acid, naringenin, quercetin etc.) significantly lowers the risk of developing many cancers.
  • Black tea polyphenols like EGCG, theaflavins and thearubigins have potent anticancer properties
  • Anti-carcinogenic effects of resveratrol are due to the antioxidant function, which inhibits hydroperoxidase, Akt (PI3K-Akt) signaling pathway, matrix metalloprotease-9, NF-kB, protein kinase C, cyclooxygenase, focal adhesion kinase and Bcl-2 (B cell lymphoma 2) biomarkers/enzymes (Athar et al., 2007)
  • Increased OS may lead to the vulnerability of the infection and also triggers the malfunctioning of cellular metabolism
  • Resveratrol shows its anti-rheumatoid arthritis properties with reduced RA patients’ swelling, tenderness, and disease activity by lowering the biochemical indicators of inflammation like MMP-3, IL-6, ESR, C-reactive protein, and undercarboxylated osteocalcin
  •  
    A good overview about polyphenols.
katherine-medina

https://assets.researchsquare.com/files/rs-2962278/v1/95a4813e-7c91-423d-8608-d3e697f79... - 0 views

    • katherine-medina
       
      A. Besides, the results implied that these stilbenes effectively inhibited the levels of adhesion and virulence genes and downregulate the production of -hemolysin. This study showed that stilbenes from pigeon pea have anti-Staphylococcus potential, and they also inhibited bacterial proliferation, biofilm formation, and key gene expressions related to adhesion and virulence of MRSA.
    • katherine-medina
       
      "Over the past few years, bacterial biofilm has aroused wide attention. And the biofilm can be called sessile microbial community where cells are attached to the surface or to other cells and can embed themselves in a protective extracellular polymeric matrix." This is a pretty interesting piece of information.
    • katherine-medina
       
      Moreover, as an ethnological herb, pigeon pea is adopted in traditional medicine for its treatments of diabetes (Al-Saeedi and Hossain 2015; Talukdar 2013), hepatic-disorder (Ghosh et al. 2006), necrosis of femoral head (Luo et al. 2009), measles (Nwodo Page 4/20 et al. 2011) and osteoporosis HUH that is really interesting considering the amount of pigeon peas I have had in arroz con gondules.
  • ...3 more annotations...
    • katherine-medina
       
      The growth cures suggested that 1 MIC and 1/2 MIC of these compounds had remarkable inhibitory effects on the MRSA growth. Wow
    • katherine-medina
       
      Additionally, the epidermis was the external barrier of the body and thus HaCaT (human keratinocyte) was used to investigate the cytotoxicity of these stilbenes. As a result, these compounds had no discernible harmful effects on HaCaT at concentrations of 1/4 of their MIC, and their IC50 on HaCaT were 9.58 ± 0.22, 12.76 ± 0.31, 18.38 ± 0.41 µg/mL, respectively. Hence, the maximum concentrations of these stilbenes were set at 1/4 MIC in the follow-up research It is quite remarkable that pigeon peas are that effective.
    • katherine-medina
       
      It is incredibly important that the article states this, "However, current researches barely reveal the anti-MRSA biofilm ability of stilbenes from pigeon pea." This makes me want to learn more and more about how pigeon pea polyphenols work mostly because it is a very unexplored area of biochemistry.
  •  
    This article is about three different stilbenes in pigeon peas that were found to fight against MRSA.
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